title: Spatial organization within a niche as a determinant of stem-cell fate.
abstract: Stem-cell niches in mammalian tissues are often heterogeneous and compartmentalized; however, whether distinct niche locations determine different stem-cell fates remains unclear. To test this hypothesis, here we use the mouse hair follicle niche and combine intravital microscopy with genetic lineage tracing to re-visit the same stem-cell lineages, from their exact place of origin, throughout regeneration in live mice. Using this method, we show directly that the position of a stem cell within the hair follicle niche can predict whether it is likely to remain uncommitted, generate precursors or commit to a differentiated fate. Furthermore, using laser ablation we demonstrate that hair follicle stem cells are dispensable for regeneration, and that epithelial cells, which do not normally participate in hair growth, re-populate the lost stem-cell compartment and sustain hair regeneration. This study provides a general model for niche-induced fate determination in adult tissues.
authors.affiliation: Department of Genetics, Department of Dermatology, Yale Stem Cell Center, Yale Cancer Center, Yale School of Medicine, New Haven, Connecticut 06510, USA.
authors.forename: Panteleimon
authors.initials: P
authors.lastname: Rompolas
authors.forename: Kailin R
authors.initials: KR
authors.lastname: Mesa
authors.forename: Valentina
authors.initials: V
authors.lastname: Greco
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D019070:Cell Lineage; D004847:Epithelial Cells / Q000166:cytology; D018859:Hair Follicle / Q000166:cytology; D008297:Male; D051379:Mice; D012038:Regeneration; D055153:Stem Cell Niche; D013234:Stem Cells / Q000166:cytology*